Packages of this kind are typically manufactured from a plane, substantially rectangular blank of a cardboard material or a comparably rigid but foldable material which is provided with a suitable crease line pattern and is formed to a tube, one end of which is given a bottom closure of any chosen kind and the other end of which is closed by means of so-called bellows folding with a sealing fin arranged on top of it formed of the edge zone of the packing container, that is to say a top closure which below the sealing fin consisting of the edge zone comprises four rectangular end panels, of which two are preferably placed obliquely to each other whilst each of the other two is divided into three triangular panels and folded in under the sealing fin to form so-called bellows folds, the sealing fin consisting, at least to the greater part, of four material layers which are joined to one another by means of a sealing operation.
In packing containers of the aforementioned type it has been a problem to make them tight and at the same time openable. It has been found impossible up to now to fulfill both these requirements in a satisfactory manner and it has been more or less unavoidable to sacrifice the tightness of the container in favour of making it easily openable.
There is a need therefore, to eliminate the said problem of the known packing containers and make available a packing container which is both easily openable and at the same time satisfactorily tight.